Carbureting device



May 26, 19,25. 1539;589

H. NATTRASS CARBURETING DEVICE Filed May 25, 1922 Patented May 26, 1925.

UNITED STATES PATENT OFFICE;

HOWABD NAT'TBASE, DE "WELLINGTON, NFJN ZEALAND, .ASSIGNOR T0 WILLIAM ED- HABJD HILLS, 0F WELLINGTON, NEW ZEALAND.

CARBUR-ETING DEVICE.

Application filed May 25, 1922.

To all whom it may concern:

Be it known that I, T-IOWARD NATTRASS, motor importer, a subject of the King of Great Britain, residing at care of Villiam Edward Wills, company director, of Jamiesons Buildings, Wellington, New Zealand, have invented certain new and useful Improvements in Carbureting; Devices, of which the following is a specification.

The present invention has reference to improvements in carburetors for use in connection with internal combustion engines and more particularly relates to that class of carburetors in which the air is drawn directly through the fuel in the fuel tank so as to form a combustible mixture and finally being drawn into the engine.

The invention consists broadly in the utilization of the petrol tank to effect the. dual purpose of being both a fuel chamber and also a mixing chamber; and the provision of means whereby the air admission into the carburetor may be locate-d at a constant or predeterminable depth beneath the fuel so that the air passes through a required depth of fuel before rising to the surface and in the provision of a further adjustable air inlet whereby the richness of the carbureted mixture may be modified as desired. The invention consists in these features and in the features and combinations and arrangements of parts hereinafter described and more par ticularly pointed out in the claims.

Referring to the accompanying drawings which illustrate one embodiment of my invention, Figure 1 is a side sectional elevation of the device showing its connection with the engine cylinder, Figure 2 is an end elevation of the device and Figure 3 is an enlarged top plan view of the swivel joint showing its attachment to the fuel tank.

Referring to the drawings there is provided a fuel tank 1 having preferably flattened sides 2 and 3 at one end to which are brazed or otherwise secured stuffing boxes 6 and 6*. Nuts 7 and 7 are adapted to screw on to the stuffing boxes 6 and 6 and compress the packings 8 and 8 to form airtight joints with a transversely disposed pipe 4 and sides 2 and 3 and to securely hold the pipe 4: in position. Between the sides 2 and 3 and inside the tank, a T shaped pipe 9 is pivotally arranged about the pipe 4, the latter also having a vertically elongated opening 10 which corresponds with the open- Serial No. 563,698.

ing in the leg 11 of the T-shaped pipe 9; A pipe 12 is soldered into, or otherwise suit ably secured to the leg 11, having its other end 13 bent downwardly at an angle. On this angularly bent end 13 is adjustably secured a float 14: preferably by a clamp 15 attached to the body of the float 14. The end 15 of the pipe is preferably closed and perforations 16 are pro-vided to allow the incoming air to be evenly diffuse-d through the surrounding fuel. It is preferable that the combined area of the perforations should not be less than the internal area of pipe 13. preferably cylindrically shaped well 17 is provided in the bottom of the tank 1 to enable the float and its arm to' act with a minimum quantity of fuel in the tank as shown in dotted lines in Figure 1. An auxiliary air inlet pipe 18 having a lateral opening 19 is attached to the top of the tank 1. A plug 20 provided with a bore 21 which corresponds to the opening 19 and is capable of being turned to open or close the opening 19 as desired, by suitable means such as the usual flexible lead 22 controllable from the steering post.

Centrally above the float 14 is a-chamber or dome secured to the tank 1 by screws 24. A preferably perforated horizontal or other suitable baffle plate 25 is located between the dome 23 and the top of tank 1 to prevent the petrol from splashing up into the dome 23 through the induction tube 28. Vertical baffle plates 26 and 27 of convenient shape preferably perforated are provided to prevent undue splashing of the petrol.

A. pipe 28 is secured at one end to the top of the dome 23 and at its other end to the underside of a valve chamber 29, which is provided with a preferably spring operated non-return valve 30, a preferably spring operated release valve 31, and a butterfly throttle valve 32 of the usualtype, the valve 32 being operable in the ordinary manner to control the speed of the engine. The valve chamber 29 is secured to the manifold 33 of the engine 34.

The inlet end of pipe 5 is protected with a gauze cover 35 and similarly the opening 19 in the auxiliary air inlet is protected with a gauze cover 36 to prevent any flame or sparks penetrating into the interior of the tank 1.

In operation, the tank 1 is partially filled with gasoline (see Figure 1) the float 14.:

causing the perforated end 16 of the pipe 13 to be submerged to a prearranged depth. The downward movement of the engine piston causing a vacuum in the combustion chamber, the non-return valve 30 is lifted off its seat and a suction is created in the pipe 28. This suction draws air from the atmosphere through the gauze cover 35 into the air inlet pipe 5 and thence through the elongated hole 10 of the T piece 9 into pipe 12, :whence it is drawn through the penfora; tions 16 of the bent end 13 passing upwards through the gasoline and combines with the vapour to form the explosive mixture.

The explosive .mixture .is drawn through the baffle iplate 25 into the dome 2'8 and passes along pipe 28,:and by the lifted valve 30 into the manifold of the engine and thence in the ordinary manner to :the combustion chamber. The air inlet 18 which is operated from the steering pillar enables the operator to effectively control .the richness of :the mixture by admitting into the tank 1, through this lchannel or supply of air which "passing freely through the vapour to the dome 23, automatically diminishing thesupply of air entering through pipe 5, by-t-he fact that the air so admitted takes a line of less resistance and automatically reduces theagitation on the fuel. This automatic equilibrium of the air admissions is obtainedby pipes 18, 5 and 28 being of the same internal diameter.

In the event of a backfire or back pressure ithesame are effectively prevented from reaching the explosive mixture in the tank by "the non-return valve30, which automatically closes and such back fire or back pressure is passed harmlessly to the atmosphere through the spring release valve 31. The tank may be provided with the ordinary filler cap.

Whatl do claim is z-- 1 Ina carburetor of the character described, a fuel containing tank including a body havinga well in the central portion of the bottomthereof and a dome in the top above the well in combination Withthe pivotally mounted float controlled air supply means, the well serving to accommodate the i lower portion of the float controlled airsupply means to ensure of the air passing through the entire contents of the tank.

2.'In a carburetor of the character described, a tank, a pipe arranged through the body of the tank and having an opening communicating with the interior of the I body, :a substantially T-shaped 'pjipe pivotally arranged'iabout the first mentioned pipe in such manner that the leg portion will coact with the opening in the first mentioned pipe, the outer 'end of the leg portion being closed and provided with perforations, and buoyant means ad-j ustaibly mounted near the "extremity of'the legportion.

3. In a carburetor 0f the character described, a tank, a .pipe arranged through the body of the tank near the top thereof and having an opening communicating with the interior of said body, a substantially T- in presence of two witnesses.

HOWARD NA' IT-RASS.

Witnesses: 7

ANDREW JOHN PARK, J r.. C. MAoKm'rosH HILL.

In testimony whereof I aflix my signature till 

